1. Field of the Invention
The present invention relates to a liquid container and a liquid ejection apparatus.
2. Related Art
For a liquid ejection apparatus for ejecting a liquid onto a target, an ink jet printer has widely been used. More specifically, the ink jet printer comprises a carriage and a recording head mounted on the carriage. The ink jet printer serves to discharge an ink from a nozzle formed on the recording head while moving the carriage with respect to a recording medium, thereby carrying out printing over the recording medium. In such an ink jet printer, moreover, an ink cartridge is exchangeably provided to be a liquid container storing an ink, and the ink discharged from the recording head is supplied from the ink cartridge.
In recent years, in the ink jet printer, printing has been carried out over a large-sized paper such as an A0 size in some cases. In these cases, an ink cartridge capable of storing an ink having a large capacity has been required because of an increase in the amount of consumption of the ink. If such an ink cartridge having a large capacity is mounted on a carriage, however, the weight of the carriage is increased so that a large load might be applied to a carriage motor. Accordingly, there has generally been employed a structure (a so-called off-carriage type) in which the ink cartridge is not mounted on the carriage.
In some ink cartridges, a space in a case is partitioned into two parts through a plastic film, and an ink bag is accommodated on one side and a waste ink absorber is accommodated on the other side (for example, see JP-A-11-70672) The ink bag includes an ink take-out port. One of the ends of an ink supply tube is connected to the ink take-out port. Moreover, the other end of the ink supply tube is connected to a recording head, and an ink in the ink bag is guided to the recording head through the ink take-out port and the ink supply tube.
Furthermore, the waste ink absorber is connected to one of the ends of a waste liquid tube through a take-in port rubber provided on the case. The other end of the waste liquid tube is connected to a cap provided for cleaning and moisturizing the nozzle of the recording head. Accordingly, a waste ink generated in the cap during the cleaning is guided to the waste ink absorber through the waste liquid tube.
In the case in which the ink cartridge is to be attached to an ink jet printer, the position of the ink bag is provided downward in the gravity direction with respect to the position of the recording head in many cases. The reason is that the ink is to be prevented from being discharged from the ink bag to the recording head, the cap, the pump and the waste ink absorber due to a head difference because the position of the ink bag is set above that of the recording head.
In recent years, however, a small-sized thin ink jet printer has been subjected to off-carriage in addition to the large-sized ink jet printer in some cases. The reason is that the layout of the ink cartridge is to have a degree of freedom. Such an ink jet printer is small-sized and thinned, and at the same time, there is a high possibility that the ink jet printer might be caused to fall down.
In such an ink jet printer, accordingly, there is a possibility that the ink bag might be provided above the recording head in the gravity direction due to the fall-down even if the ink cartridge is provided with the ink bag set below the recording head in the gravity direction. As a result, there is a possibility that the ink might be discharged from the ink bag to the recording head, the cap, the sucking pump and the waste ink absorber, resulting in the wasteful consumption of the ink.